Printing and display device

ABSTRACT

A printing and display device comprising: a flat panel display for displaying images from a computer; and a printer, the printer including a printhead for printing onto the paper.

FIELD OF INVENTION

[0001] The present invention relates to an integrated printing and flatpanel display unit.

[0002] The invention has been developed primarily as an integratedperipheral unit that is connectable to a personal computer such asMacintosh or IBM compatible PC. However, it will be appreciated by thoseskilled in the art that the invention is not limited to theseapplications.

CO-PENDING APPLICATIONS

[0003] Various methods, systems and apparatus relating to the presentinvention are disclosed in the following co-pending applications filedby the applicant or assignee of the present invention simultaneouslywith the present application: FPD002US, FPD003US, FPD004US, FPD005US,FPD006US, FPD007US

[0004] The disclosures of these co-pending applications are incorporatedherein by cross-reference. Each application is temporarily identified byits docket number. This will be replaced by the correspondingapplication number when available.

CROSS-REFERENCES

[0005] Various methods, systems and apparatus relating to the presentinvention are disclosed in the following co-pending applications filedby the applicant or assignee of the present invention. The disclosuresof all of these co-pending applications are incorporated herein bycross-reference. PEA01US PEA02US PEA03US PEA04US PEA05US PEA06US PEA07USPEA08US PEA09US PEA10US PEA11US PEA12US PEA13US PEA14US PEA15US PEA16USPEA17US PEA18US PEA19US PEA21US PEA23US PEA24US PEA25US PEA26US PEA27USPEA28US 09/575,197 09/575,187

[0006] Some applications are temporarily identified by docket numbers.These will be replaced by the corresponding application numbers whenavailable.

BACKGROUND

[0007] Flat panel displays are known A popular technology presently inuse is the Thin Film Transistor (TFT) Liquid Crystal Display (LCD),which comprises an array of liquid crystal pixel elements driven byrespective thin film transistors. In each element, liquid crystal issandwiched between glass plates. A backlight is positioned behind theLCD layer relative to a position from which the display will be viewed.A polarizing screen is placed between the backlight and the LCD layer,and another polarizing screen is positioned on the other side of the LCDlayer. The polarizing screens are orientated to be orthogonallypolarizing with respect to each other.

[0008] Using the corresponding TFT to alter a voltage applied to theliquid crystal element causes a change in its crystalline structure thatcorrespondingly alters the polarization of light passing through theelement from the backlight. This change in polarization causes acorresponding change in the amount of light transmitted through thepolarizing screens and LCD element.

[0009] Multiple colors are dealt with by providing each pixel withmultiple LCD pixel elements (usually red, green and blue) that canindividually be controlled for each pixel, thereby allowing variouscolor combinations.

[0010] The design and operation of TFT LCD screens is well known tothose skilled in the art and so is not described in more detail in thisdocument.

[0011] Typically, flat panel displays, including TFT LCD displays, aremore expensive than Cathode Ray Tube (CRT) display of comparableperformance. However, the relative lightness and compactness of flatpanel displays (particularly in terms of front to back depth) make themparticularly suitable for situations where a small footprint isdesirable. They are ubiquitous in laptop computers, and have come downin price sufficiently for them to be attractive to many desktop computerusers. The relatively shallow front to back depth means that the displaycan be pushed back further from the user than would be possible with aCRT in many situations, thereby allowing better viewing comfort. Flatpanel displays also enable a user to utilize considerably smaller areasthan would be possible with an equivalent CRT display, which can beimportant in situations where a wall, partition or divider is locatedclose to a work area in which the display is to be situated.

[0012] Often, computer users wish to print a hard copy of documents,images, web pages and the like. Usually, a printer is provided as aperipheral device that can be connected to the computer using a suitablecable. Alternatively, the computer can be connected via a Local AreaNetwork (LAN) or other communications network Printers can be bulky, andtend to take up additional space in a user's work area. Where space isat a premium, such printers can be intrusive or at least inconvenient.In many cases where a flat panel display is selected, space is alreadyat a premium, so printers can exacerbate the problem.

SUMMARY OF THE INVENTION

[0013] In one aspect the present invention provides a printing anddisplay device comprising: a flat panel display for displaying imagesfrom a computer; and a printer, the printer including a printhead forprinting onto the paper.

[0014] In a second aspect the present invention provides a printing anddisplay device comprising: a flat panel display for displaying imagesfrom a computer; a stand for holding the flat panel display in anoperative position; and a printer, the printer including a printhead forprinting onto paper; wherein the stand includes at least one receptacleconfigured to accept at least one replaceable ink cartridge forsupplying ink to the printer.

[0015] In a third aspect the present invention provides a printing anddisplay device comprising: a data connection for receiving print datafrom a computer; a flat panel display for displaying images receivedfrom a computer; a printer, the printer including a printhead forprinting onto paper on the basis of the print data; and a dataconnection hub configured to allow connection of at least onedata-receiving device to the printing and display device, enabling thedata-receiving device to receive data from the computer.

[0016] In a fourth aspect the present invention provides a printing anddisplay device comprising:

[0017] a. a flat panel display; and

[0018] b. a printer, including a printhead for printing onto paper;

[0019] c. the device being configured such that, during printing, thepaper being printed passes between the flat panel display and theprinthead, or passes behind the flat panel display and the printheadrelative to a viewing position of the flat panel display.

[0020] In a fifth aspect the present invention provides a printing anddisplay device comprising:

[0021] a. a flat panel display;

[0022] b. a printer, including a printhead for printing onto paper;

[0023] c. a multi-sheet paper holder;

[0024] d. a paper sheet separator configured to separate a single papersheet from the paper in the paper holder for supply to the printhead.

[0025] In a sixth aspect the present invention provides a printing anddisplay device comprising:

[0026] a. a flat panel display for displaying images from a computer;and

[0027] b. a printer, the printer including at least two the printheads,the printheads being disposed on either side of a path through whichprint media is fed for printing, thereby enabling substantiallysimultaneous printing of both sides of the print media.

[0028] In a seventh aspect the present invention provides a printerconfigured to receive documents to be printed from a computer system,the printer including an interface, and being configured to:

[0029] receive, via the interface, input from a user indicative of aprint command;

[0030] send, from the printer to the computer system, a print request;

[0031] receive, from the computer system and in response to the printrequest, a document to be printed; and

[0032] print the document.

[0033] The invention will be more fully understood from the followingdescription of an embodiment of a printing and display device thatincorporates an exemplified form of the invention. The description isprovided with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0034] Preferred embodiments of the invention will now be described, byway of example only, with reference to the accompanying drawings, inwhich:

[0035]FIG. 1 is a schematic of document data flow in a printing system;

[0036]FIG. 2 is a more detailed schematic showing an architecture usedin the printing system of FIG. 1;

[0037]FIG. 3 is a data representation of page element used in theprinting system of FIG. 1,

[0038]FIG. 4 is a schematic showing CMOS drive and control blocks foruse with the printer of FIG. 1;

[0039]FIG. 5 is a schematic showing the relationship between nozzlecolumns and dot shift registers in the CMOS blocks of FIG. 4;

[0040]FIG. 6 is a more detailed schematic showing a unit cell and itsrelationship to the nozzle columns and dot shift registers of FIG. 5;

[0041]FIG. 7 is a circuit diagram showing logic for a single printernozzle in the printer of FIG. 1;

[0042]FIG. 8 is a perspective view of a flat panel display incorporatinga printer, in accordance with the invention;

[0043]FIG. 9 is a perspective view of the flat panel display of FIG. 8,whilst printing a page;

[0044]FIG. 10 is a rear perspective view of the flat panel display ofFIG. 8;

[0045]FIG. 11 is a front elevation of the flat panel display of FIG. 9;

[0046]FIG. 12 is a right-hand side elevation of the flat panel displayof FIG. 9;

[0047]FIG. 13 is a plan view of the flat panel display of FIG. 9;

[0048]FIG. 14 is a left-hand side elevation of the flat panel display ofFIG. 9;

[0049]FIG. 15 is a rear elevation of the flat panel display of FIG. 9;

[0050]FIG. 16 is a perspective exploded view of the flat panel displayof FIG. 8;

[0051]FIG. 17 is a rear perspective view of the flat panel display ofFIG. 8 with the stand detached;

[0052]FIG. 18 is a rear perspective view of the flat panel display ofFIG. 8 with the rear cover removed;

[0053]FIG. 19 is a rear perspective view of the flat panel display ofFIG. 8 with the shields removed;

[0054]FIG. 20 is a rear perspective view of the flat panel display ofFIG. 8 showing the core electrical and electronic components;

[0055]FIG. 21 is a perspective view of interconnected printed circuitboards used in the flat panel display of FIG. 8;

[0056]FIG. 22 is a perspective view of the print engine used in the flatpanel display of FIG. 8;

[0057]FIG. 23 is a perspective view of the print engine of FIG. 22, withsome componentry removed to reveal the printhead;

[0058]FIG. 24 is a vertical section along the centerline of the flatpanel display of FIG. 8;

[0059]FIG. 25 is an enlarged detail view of the vertical section of FIG.24;

[0060]FIG. 26 is an enlarged detail view of a vertical section of asecond embodiment of a flat panel display incorporating a duplexprinthead, in accordance with the invention;

[0061]FIG. 27 is a vertical section along the centerline of a thirdembodiment of a flat panel display incorporating a multi-sheet paperfeeder, in accordance with the invention;

[0062]FIG. 28 is an enlarged detail view of the vertical section of FIG.27

[0063]FIG. 29 is a rear perspective view of an alternative embodiment ofa flat panel display including power and data connections in its base,in accordance with the invention;

[0064]FIG. 30 is a rear perspective view of an alternative embodiment ofa flat panel display including a power input, data inputs and dataoutputs in its base, in accordance with the invention;

[0065]FIG. 31 is a rear perspective view of an alternative embodiment ofa flat panel display including power and data connections in its baseand an ink cartridge in its mounting plate, in accordance with theinvention;

[0066]FIG. 32 is a rear perspective view of an alternative embodiment ofa flat panel display including an ink cartridge, a power input and dataconnections in its base, in accordance with the invention;

[0067]FIG. 33 is a perspective view of a bi-lithic printhead for use inthe flat panel display of FIG. 8;

[0068]FIG. 34 is a rear perspective view of the bi-lithic printhead ofFIG. 33;

[0069] FIGS. 35(a) to 35(d) show a side elevation, plan view, oppositeside elevation and reverse plan view, respectively, of the bi-lithicprinthead of FIG. 33;

[0070]FIGS. 36 and 37 show enlarged end views of the bi-lithic printheadof FIG. 33;

[0071]FIG. 38 shows an enlarged detail plan view of one end of thebi-lithic printhead of FIG. 33;

[0072]FIG. 39 is a sectional view taken along line 45-45 in FIG. 38;

[0073]FIG. 40 is an enlarged detail perspective view of one end of thebi-lithic printhead of FIG. 33;

[0074]FIG. 41 is an enlarged detail perspective view of an opposite endof the bi-lithic printhead of FIG. 33;

[0075]FIG. 42 is an exploded perspective view of the bi-lithic printheadof FIG. 33;

[0076]FIG. 43 is a sectional view taken along line 49-49 in FIG. 38;

[0077]FIG. 44 is a schematic view showing the components of the flatpanel display of FIG. 8;

[0078]FIG. 45 is a schematic view of a print engine chip incorporated inthe flat panel display of FIG. 8;

[0079]FIG. 46 is a vertical sectional view of a single nozzle forejecting ink, for use with the invention, in a quiescent state;

[0080]FIG. 47 is a vertical sectional view of the nozzle of FIG. 46during an initial actuation phase;

[0081]FIG. 48 is a vertical sectional view of the nozzle of FIG. 57later in the actuation phase;

[0082]FIG. 49 is a perspective partial vertical sectional view of thenozzle of FIG. 48, at the actuation state shown in FIG. 48;

[0083]FIG. 50 is a perspective vertical section of the nozzle of FIG.46, with ink omitted;

[0084]FIG. 51 is a vertical sectional view of the of the nozzle of FIG.50;

[0085]FIG. 52 is a perspective partial vertical sectional view of thenozzle of FIG. 46, at the actuation state shown in FIG. 47;

[0086]FIG. 53 is a plan view of the nozzle of FIG. 46;

[0087]FIG. 54 is a plan view of the nozzle of FIG. 46 with the lever armand movable nozzle removed for clarity;

[0088]FIG. 55 is a perspective vertical sectional view of a part of aprinthead chip incorporating a plurality of the nozzle arrangements ofthe type shown in FIG. 46.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

[0089] As shown in FIG. 1, in the preferred embodiment, the printingaspect of the invention is embodied in an A4/Letter printer 100 thatprints documents supplied by a computer system 102. The computer system102 is programmed to perform various steps involved in printing adocument, including receiving the document (step 103), buffering it(step 104) and rasterizing it (step 106), and then compressing it (step108) for transmission to the printer 100.

[0090] The compressed, multi-layer page image is buffered (step 110)upon receipt in the printer 100, then expanded (step 112). The expandedcontone layer is dithered (step 114) and then the black layer from theexpansion step is composited over the dithered contone layer (step 116).Coded data can also be rendered (step 118) to form an additional layer,to be printed (in the preferred form) using an infrared ink that issubstantially invisible to the human eye. The black, dithered contoneand infrared layers are combined (step 120) to form a page that issupplied to a printhead for printing (step 122). In the preferredembodiment, the printhead is a bi-lithic printhead configured to printin 6 colors in a pagewidth format, although the design can be adapted toprint using any desired number of colors, and can be monolithic orrequire multiple substrates depending upon implementation.

[0091] The preferred embodiment divides printer data into ahigh-resolution bi-level mask layer for text and line art and amedium-resolution contone color image layer for images or backgroundcolors. Optionally, colored text can be supported by the addition of amedium-to-high-resolution contone texture layer for texturing text andline art with color data taken from an image or from flat colors. Thepreferred printing architecture, elements of which are described in moredetail below, generalises these contone layers by representing them inabstract “image” and “texture” layers which can refer to either imagedata or flat color data. This division of data into layers based oncontent follows the base mode Mixed Raster Content (MRC) model specifiedin ITU-T.44. Like the MRC base mode, the preferred printing architecturemakes compromises in some cases when data to be printed overlap. Inparticular, in the preferred form all overlaps are reduced to a 3-layerrepresentation in a process (collision resolution) embodying thecompromises explicitly.

[0092] As shown in FIG. 3, the central data structure for the preferredprinting architecture is a generalised representation of the threelayers, called a page element. A page element can be used to representunits ranging from single rendered elements emerging from a renderingengine up to an entire band of a print job. FIG. 3 shows a simplifiedUML diagram of a page element 300. Conceptually, the bi-level symbolregion selects between the two color sources, as described in moredetail below.

[0093] Printing Architecture

[0094] A more detailed description of the printing architecture will nowbe described with reference to FIGS. 2 and 3. It will be appreciatedthat the components of the architecture 208 shown in FIG. 2 willtypically be device dependent, in that they process the data into a formrequired by a software or hardware component further downstream.

[0095] In FIG. 2, a renderer 209 exists outside of the more generalprinter system pipeline. Its purpose is to render files to be printedand deliver rendered elements to the data receiver 210 of the pipeline,using an API (“Application Programming Interface”) exposed by the datareceiver 210 for that purpose. The rendered elements are delivered inorder according to the painter's algorithm, which is well known to thoseskilled in the art of image processing. The data passed in through theAPI is converted by the data receiver 210 into lists of dictionaries andpage elements for processing in later stages.

[0096] A collision resolver 211 accepts the simple page elements createdby the data receiver and creates a fully opaque “resolved” page elementfor each intersection of a new element with the background and anyelements already present. Fundamentally, the collision resolverguarantees that the entire page is tiled with opaque elements.

[0097] A stripper 212 divides a band of data into horizontallyoverlapping pieces. This need only be performed in the case whererelatively wide or fast printers use multiple parallel devices in orderto achieve the required output dot-rate. In such cases, eachhorizontally overlapping piece is fed into a corresponding devicedownstream. Where such data division is not required, the stripper 212can be omitted.

[0098] Different printing configurations will require differentconfigurations of layers for delivery to the downstream hardware. Alayer reorganiser 213 converts 3-layer page elements to the appropriate2- or 3-layer form for the specific configuration. Again, there may becases in which this function is not required, in which case the layerorganiser can be omitted.

[0099] A contone combiner 214 combines and clips the image and texturelayers of all page elements in a strip into single image and texturelayers, as required by downstream hardware.

[0100] A color converter 215 transforms the contone planes of all pageelements from the input color space to a device-specific color space(which is usually CMYK).

[0101] A mask combiner 216 performs the same operation on the mask layeras the contone combiner performs on the contone layers. All elements areclipped to a strip boundary and drawn into a single mask buffer.

[0102] A densitometer 218 measures the density of the current page as apercentage of total possible density. This operation is necessary onlyin low-end printers with power supplies that may not be able to handle afully dense page at full speed.

[0103] A contone compressor 220 compresses the contone layers of allpage elements in order to reduce downstream memory and/or transmissionbandwidth requirements.

[0104] A mask formatter 222 converts the mask layer of page elements,which may be represented as regions of placed symbol references, intothe form expected by a downstream mask decompressor.

[0105] A size limiter 224 ensures that all size limitations, for bandsand for entire pages, are adhered to, by either dividing bands intosmaller bands or by recompressing the data, repeating until theconstraint is satisfied.

[0106] If data is to be transmitted to the printer between pipelinestages, a serialised form of the data structures is generated (inserialiser 226), transmitted, then deserialised (in deserialiser 228).

[0107] Within the printer, a distributor 230 converts data from aproprietary representation into a hardware-specific representation andensures that the data for each strip is sent to the correct hardwaredevice whilst observing any constraints or requirements on datatransmission to these devices. The distributor distributes the converteddata to an appropriate one of a plurality of pipelines 232. Thepipelines are identical to each other, and in essence providedecompression, scaling and dot compositing functions to generate a setof printable dot outputs.

[0108] Each pipeline 232 includes a buffer 234 for receiving the data. Acontone decompressor 236 decompresses the color contone planes, and amask decompressor 238 decompresses the monotone (text) layer. Contoneand mask scalers 240 and 242 scale the decompressed contone and maskplanes respectively, to take into account the size of the medium ontowhich the page is to be printed.

[0109] The scaled contone planes are then dithered by ditherer 244. Inthe preferred form, a stochastic dispersed-dot dither is used. Unlike aclustered-dot (or amplitude-modulated) dither, a dispersed-dot (orfrequency-modulated) dither reproduces high spatial frequencies (i.e.image detail) almost to the limits of the dot resolution, whilesimultaneously reproducing lower spatial frequencies to their full colordepth, when spatially integrated by the eye. A stochastic dither matrixis carefully designed to be relatively free of objectionablelow-frequency patterns when tiled across the image. As such, its sizetypically exceeds the minimum size required to support a particularnumber of intensity levels (e.g. 16×16×8 bits for 257 intensity levels).

[0110] The dithered planes are then composited in a dot compositor 246on a dot-by-dot basis to provide dot data suitable for printing. Thisdata is forwarded to data distribution and drive circuitry 248, which inturn distributes the data to the correct nozzle actuators 250, which inturn cause ink to be ejected from the correct nozzles 252 at the correcttime. This process is described in more detail below.

[0111] The architecture 208 includes a mainly software-based computersystem portion prior to the serialiser 226, and a mainly hardware-basedprinter portion that is located within a printer remote from thecomputer system, which includes everything from the deserialiser 228onwards. It will be appreciated, however, that the indicated divisionbetween computer system and printer is somewhat arbitrary, and variouscomponents can be placed on different sides of the divide withoutsubstantially altering the operation of the architecture as a whole. Itwill also be appreciated that some of the components in the architecture208 can be handled in hardware or software remotely from the maincomputer system and printer. For example, rather than relying on thegeneral-purpose processor of a personal computer, some of the componentsin the architecture can be accelerated using dedicated hardware.

[0112] SoPEC Device

[0113] In the preferred form, the hardware pipelines 232 are embodied ina Small Office Home Office Printer Engine Controller (SoPEC), as shownin FIG. 2 and described in more detail below. The printer preferablyalso includes one or more system on a chip (SoC) components, as well asthe print engine pipeline control application specific logic, configuredto perform some or all of the functions described above in relation tothe printing pipeline.

[0114] As shown in FIG. 45, from the highest point of view a SoPECdevice consists of 3 distinct subsystems: a Central Processing Unit(CPU) subsystem 301, a Dynamic Random Access Memory (DRAM) subsystem 302and a Print Engine Pipeline (PEP) subsystem 303.

[0115] The CPU subsystem 301 includes a CPU 30 that controls andconfigures all aspects of the other subsystems. It provides generalsupport for interfacing and synchronizing the external printer with theinternal print engine. It also controls the low-speed communication toQA chips (which are described elsewhere in this specification). The CPUsubsystem 301 also contains various peripherals to aid the CPU, such asGeneral Purpose Input Output (GPIO, which includes motor control), anInterrupt Controller Unit (ICU), LSS Master and general timers. TheSerial Communications Block (SCB) on the CPU subsystem provides a fullspeed USB 1.1 interface to the host as well as an Inter SoPEC Interface(ISI) to other SoPEC devices (not shown).

[0116] The DRAM subsystem 302 accepts requests from the CPU, SerialCommunications Block (SCB) and blocks within the PEP subsystem. The DRAMsubsystem 302, and in particular the DRAM Interface Unit (DIU),arbitrates the various requests and determines which request should winaccess to the DRAM. The DIU arbitrates based on configured parameters,to allow sufficient access to DRAM for all requestors. The DIU alsohides the implementation specifics of the DRAM such as page size, numberof banks and refresh rates.

[0117] The Print Engine Pipeline (PEP) subsystem 303 accepts compressedpages from DRAM and renders them to bi-level dots for a given print linedestined for a printhead interface that communicates directly with up to2 segments of a bi-lithic printhead. The first stage of the pageexpansion pipeline is the Contone Decoder Unit (CDU), Lossless Bi-levelDecoder (LBD) and Tag Encoder (TE). The CDU expands the JPEG-compressedcontone (typically CMYK) layers, the LBD expands the compressed bi-levellayer (typically K), and the TE encodes Netpage tags for later rendering(typically in IR or K ink). The output from the first stage is a set ofbuffers: the Contone FIFO unit (CFU), the Spot FIFO Unit (SFU), and theTag FIFO Unit (TFU). The CFU and SFU buffers are implemented in DRAM.

[0118] The second stage is the Halftone Compositor Unit (HCU), whichdithers the contone layer and composites position tags and the bi-levelspot layer over the resulting bi-level dithered layer.

[0119] A number of compositing options can be implemented, dependingupon the printhead with which the SoPEC device is used. Up to 6 channelsof bi-level data are produced from this stage, although not all channelsmay be present on the printhead. For example, the printhead may be CMYonly, with K pushed into the CMY channels and IR ignored. Alternatively,the encoded tags may be printed in K if IR ink is not available (or fortesting purposes).

[0120] In the third stage, a Dead Nozzle Compensator (DNC) compensatesfor dead nozzles in the printhead by color redundancy and errordiffusing of dead nozzle data into surrounding dots.

[0121] The resultant bi-level 6 channel dot-data (typically CMYK,Infrared, Fixative) is buffered and written to a set of line buffersstored in DRAM via a Dotline Writer Unit (DWU).

[0122] Finally, the dot-data is loaded back from DRAM, and passed to theprinthead interface via a dot FIFO. The dot FIFO accepts data from aLine Loader Unit (LLU) at the system clock rate bclk), while thePrintHead Interface (PHI) removes data from the FIFO and sends it to theprinthead at a rate of 2/3 times the system clock rate.

[0123] In the preferred form, the DRAM is 2.5 Mbytes in size, of whichabout 2 Mbytes are available for compressed page store data. Acompressed page is received in two or more bands, with a number of bandsstored in memory. As a band of the page is consumed by the PEP subsystem303 for printing, a new band can be downloaded. The new band may be forthe current page or the next page.

[0124] Using banding it is possible to begin printing a page before thecomplete compressed page is downloaded, but care must be taken to ensurethat data is always available for printing or a buffer under-run mayoccur.

[0125] The embedded USB 1.1 device accepts compressed page data andcontrol commands from the host PC, and facilitates the data transfer toeither the DRAM (or to another SoPEC device in multi-SoPEC systems, asdescribed below).

[0126] Multiple SoPEC devices can be used in alternative embodiments,and can perform different functions depending upon the particularimplementation. For example, in some cases a SoPEC device can be usedsimply for its onboard DRAM, while another SoPEC device attends to thevarious decompression and formatting functions described above. This canreduce the chance of buffer under-run, which can happen in the eventthat the printer commences printing a page prior to all the data forthat page being received and the rest of the data is not received intime. Adding an extra SoPEC device for its memory buffering capabilitiesdoubles the amount of data that can be buffered, even if none of theother capabilities of the additional chip are utilized.

[0127] Each SoPEC system can have several quality assurance (QA) devicesdesigned to cooperate with each other to ensure the quality of theprinter mechanics, the quality of the ink supply so the printheadnozzles will not be damaged during prints, and the quality of thesoftware to ensure printheads and mechanics are not damaged.

[0128] Normally, each printing SoPEC will have an associated printer QA,which stores information printer attributes such as maximum print speed.An ink cartridge for use with the system will also contain an ink QAchip, which stores cartridge information such as the amount of inkremaining. The printhead also has a QA chip, configured to act as a ROM(effectively as an EEPROM) that stores printhead-specific informationsuch as dead nozzle mapping and printhead characteristics. The CPU inthe SoPEC device can optionally load and run program code from a QA Chipthat effectively acts as a serial EEPROM. Finally, the CPU in the SoPECdevice runs a logical QA chip (ie, a software QA chip).

[0129] Usually, all QA chips in the system are physically identical,with only the contents of flash memory differentiating one from theother.

[0130] Each SoPEC device has two LSS system buses that can communicatewith QA devices for system authentication and ink usage accounting. Alarge number of QA devices can be used per bus and their position in thesystem is unrestricted with the exception that printer QA and ink QAdevices should be on separate LSS busses.

[0131] In use, the logical QA communicates with the ink QA to determineremaining ink. The reply from the ink QA is authenticated with referenceto the printer QA. The verification from the printer QA is itselfauthenticated by the logical QA, thereby indirectly adding an additionalauthentication level to the reply from the ink QA.

[0132] Data passed between the QA chips, other than the printhead QA, isauthenticated by way of digital signatures. In the preferred embodiment,HMAC-SHA1 authentication is used for data, and RSA is used for programcode, although other schemes could be used instead.

[0133] A single SoPEC device can control two bi-lithic printheads and upto six color channels. Six channels of colored ink are the expectedmaximum in a consumer SOHO, or office bi-lithic printing environment,and include:

[0134] CMY (cyan, magenta, yellow), for regular color printing.

[0135] K (black), for black text, line graphics and gray-scale printing.

[0136] IR (infrared), for Netpage-enabled applications.

[0137] F (fixative), to enable printing at high speed.

[0138] Because the bi-lithic printer is capable of printing so fast, afixative may be required to enable the ink to dry before the pagetouches the page already printed. Otherwise ink may bleed between pages.In relatively low-speed printing environments the fixative may not berequired.

[0139] In the preferred form, the SoPEC device is color space agnostic.Although it can accept contone data as CMYX or RGBX, where X is anoptional 4th channel, it also can accept contone data in any print colorspace. Additionally, SoPEC provides a mechanism for arbitrary mapping ofinput channels to output channels, including combining dots for inkoptimization and generation of channels based on any number of otherchannels. However, inputs are typically CMYK for contone input, K forthe bi-level input, and the optional Netpage tag dots are typicallyrendered to an infrared layer. A fixative channel is typically generatedfor fast printing applications.

[0140] In the preferred form, the SoPEC device is also resolutionagnostic. It merely provides a mapping between input resolutions andoutput resolutions by means of scale factors. The expected outputresolution for the preferred embodiment is 1600 dpi, but SoPEC actuallyhas no knowledge of the physical resolution of the Bi-lithic printhead.

[0141] In the preferred form, the SoPEC device is page-length agnostic.Successive pages are typically split into bands and downloaded into thepage store as each band of information is consumed.

[0142] The following three tables show the constituents of each of thethree distinct subsystems which make up the SoPEC device. In particular,each of the columns provide the unit acronym, the unit name and adescription of the functions performed by each unit. Unit SubsystemAcronym Unit Name Description DRAM DIU DRAM Provides interface for DRAMread interface unit and write access for the various SoPEC units, CPUand the SCB block. The DIU provides arbitration between competing unitsand controls DRAM access. DRAM Embedded 20 Mbits of embedded DRAM. DRAM

[0143] Unit Subsystem Acronym Unit Name Description CPU CPU CentralProcessing Unit CPU for system configuration and control. MMU MemoryManagement Unit Limits access to certain memory address areas in CPUuser mode. RDU Real-time Debug Unit Facilitates the observation of thecontents of most of the CPU addressable registers in SoPEC, in additionto some pseudo-registers in real time. TIM General Timer Containswatchdog and general system timers. LSS Low Speed Serial Interfaces Lowlevel controller for interfacing with the QA chips GPIO General PurposeIOs General IO controller, with built-in Motor control unit, LED pulseunits and de-glitch circuitry ROM Boot ROM 16 KBytes of System Boot ROMcode ICU Interrupt Controller Unit General Purpose interrupt controllerwith configurable priority, and masking. CPR Clock, Power and Resetblock Central Unit for controlling and generating the system clocks andresets and powerdown mechanisms PSS Power Save Storage Storage retainedwhile system is powered down USB Universal Serial Bus Device USB devicecontroller for interfacing with the host USB. ISI Inter-SoPEC InterfaceISI controller for data and control communication with other SoPECs in amulti-SoPEC system SCB Serial Communication Block Contains both the USBand ISI blocks.

[0144] Unit Subsystem Acronym Unit Name Description Print Engine PCU PEPcontroller Provides external CPU with the means Pipeline to read andwrite PEP Unit registers, (PEP) and read and write DRAM in single 32-bit chunks. CDU Contone Decoder Unit Expands JPEG compressed contonelayer and writes decompressed contone to DRAM CFU Contone FIFO UnitProvides line buffering between CDU and HCU LBD Lossless Bi-levelDecoder Expands compressed bi-level layer. SFU Spot FIFO Unit Providesline buffering between LBD and HCU TE Tag Encoder Encodes tag data intoline of tag dots. TFU Tag FIFO Unit Provides tag data storage between TEand HCU HCU Halftoner Compositor Unit Dithers contone layer andcomposites the bi-level spot and position tag dots. DNC Dead NozzleCompensator Compensates for dead nozzles by color redundancy and errordiffusing dead nozzle data into surrounding dots. DWU Dotline WriterUnit Writes out the 6 channels of dot data for a given printline to theline store DRAM LLU Line Loader Unit Reads the expanded page image fromline store, formatting the data appropriately for the bi-lithicprinthead. PHI PrintHead Interface Responsible for sending dot data tothe bi-lithic printheads and for providing line synchronization betweenmultiple SoPECs. Also provides test interface to printhead such astemperature monitoring and Dead Nozzle Identification.

[0145] Printhead Mechanical

[0146] In the preferred form, a Memjet printer has two printheadintegrated circuits that are mounted adjacent each other to form apagewidth printhead. Typically, the printhead ICs can vary in size from2 inches to 8 inches, so several combinations can be used to produce,say, an A4 pagewidth printhead. For example two printhead ICs of 7 and 3inches, 2 and 4 inches, or 5 and 5 inches could be used to create an A4printhead (the notation is 7:3). Similarly 6 and 4 (6:4) or 5 and 5(5:5) combinations can be used. An A3 printhead can be constructed from8 and 6-inch printhead integrated circuits, for example. Forphotographic printing, particularly in camera, smaller printheads can beused. It will also be appreciated that a single printhead integratedcircuit, or more than two such circuits, can also be used to achieve therequired printhead width.

[0147] A preferred printhead embodiment will now be described withreference to FIGS. 33 to 43. As best shown in FIGS. 33 to 35 and FIG.42, a printhead 420 takes the form of an elongate unit. As best shown inFIG. 42, the components of the printhead 420 include a support member421, a flexible PCB 422, an ink distribution molding 423, an inkdistribution plate 424, a MEMS printhead comprising first and secondprinthead integrated circuits (ICs) 425 and 426, and busbars 427.

[0148] The support member 421 is can be formed from any suitablematerial, such as metal or plastic, and can be extruded, molded orformed in any other way. The support member 421 should be strong enoughto hold the other components in the appropriate alignment relative toeach other whilst stiffening and strengthening the printhead as a whole.

[0149] The flexible PCB extends the length of the printhead 420 andincludes first and second electrical connectors 428 and 429. Theelectrical connectors 428 and 429 correspond with the flexibleconnectors 147 shown FIG. 22. The electrical connectors include contactareas 148 and 159 that, in use, are positioned in contact withcorresponding output connectors (not shown) from the SoPEC chip 166(FIG. 21). Data from the SoPEC chip 166 passes along the electricalconnectors 428 and 429, and is distributed to respective ends of thefirst and second printhead ICs 425 and 426.

[0150] As shown in FIG. 43, the ink distribution molding 423 includes aplurality of elongate conduits 430 that distribute fluids (ie, coloredinks, infrared ink and fixative) and pressurized air from the air pumpalong the length of the printhead 420 (FIG. 42). Sets of fluid apertures431 (FIG. 39) disposed along the length of the ink distribution molding423 distribute the fluids and air from the conduits 430 to the inkdistribution plate 424. The fluids and air are supplied via nozzles 440formed on a plug 441 (FIG. 35), which plugs into a corresponding socket(not shown) in the printer.

[0151] The distribution plate 424 is a multi-layer constructionconfigured to take fluids provided locally from the fluid apertures 431and distribute them through smaller distribution apertures 432 into theprinthead ICs 425 and 426 (as shown in FIG. 39).

[0152] The printhead ICs 425 and 426 are positioned end to end, and areheld in contact with the distribution plate 424 so that ink from thesmaller distribution apertures 432 can be fed into correspondingapertures (not shown) in the printhead ICs 425 and 426.

[0153] The busbars 427 are relatively high-capacity conductorspositioned to provide drive current to the actuators of the printheadnozzles (described in detail below). As best shown in FIGS. 39 to 41,the busbars 427 are retained in position at one end by a socket 433, andat both ends by wrap-around wings 434 of the flexible PCB 422. Thebusbars also help hold the printhead ICs 425 in position, as best shownin FIGS. 38, 40 and 41.

[0154] As shown best in FIGS. 40, 41 and 42, when assembled, theflexible PCB 422 is effectively wrapped around the other components,thereby holding them in contact with each other. Notwithstanding thisbinding effect, the support member 421 provides a major proportion ofthe required stiffness and strength of the printhead 420 as a whole.

[0155] Printhead CMOS

[0156] Turning now to FIGS. 4 to 7, a preferred embodiment of theprinthead 420 (comprising printhead ICs 425 and 426) will be describedFor clarity, only one printhead IC 425 is shown in FIG. 4, but it willbe appreciated that a corresponding arrangement is implemented for theprinthead IC 426.

[0157]FIG. 4 shows an overview of printhead IC 425 and its connectionsto the SoPEC device 166. Printhead IC 425 includes a nozzle core array401 containing the repeated logic to fire each nozzle, and nozzlecontrol logic 402 to generate the timing signals to fire the nozzles.The nozzle control logic 402 receives data from the SoPEC chip 166 via ahigh-speed link. In the preferred form, a single SoPEC chip 166 feedsthe two printhead ICs 425 and 426 with print data.

[0158] The nozzle control logic 402 is configured to send serial data tothe nozzle array core for printing, via a link 407, which for printhead425 is the electrical connector 428. Status and other operationalinformation about the nozzle array core 401 is communicated back to thenozzle control logic via another link 408, which is also provided on theelectrical connector 428.

[0159] The nozzle array core 401 is shown in more detail in FIGS. 5 and6. In FIG. 5, it will be seen that the nozzle array core comprises anarray of nozzle columns 501. The array includes a fire/select shiftregister 502 and up to 6 color channels, each of which is represented bya corresponding dot shift register 503.

[0160] As shown in FIG. 6, the fire/select shift register 502 includesforward path fire shift register 600, a reverse path fire shift register601 and a select shift register 602. Each dot shift register 503includes an odd dot shift register 603 and an even dot shift register604. The odd and even dot shift registers 603 and 604 are connected atone end such that data is clocked through the odd shift register 603 inone direction, then through the even shift register 604 in the reversedirection. The output of all but the final even dot shift register isfed to one input of a multiplexer 605. This input of the multiplexer isselected by a signal (corescan) during post-production testing. Innormal operation, the corescan signal selects dot data input Dot[x]supplied to the other input of the multiplexer 605. This causes Dot[x]for each color to be supplied to the respective dot shift registers 503.

[0161] A single column N will now be described with reference to FIG. 6.In the embodiment shown, the column N includes 12 data values,comprising an odd data value 606 and an even data value 607 for each ofthe six dot shift registers. Column N also includes an odd fire value608 from the forward fire shift register 600 and an even fire value 609from the reverse fire shift register 601, which are supplied as inputsto a multiplexer 610. The output of the multiplexer 610 is controlled bythe select value 611 in the select shift register 602. When the selectvalue is zero, the odd fire value is output, and when the select valueis one, the even fire value is output.

[0162] Each of the odd and even data values 606 and 607 is provided asan input to corresponding odd and even dot latches 612 and 613respectively.

[0163] Each dot latch and its associated data value form a unit cell,such as unit cell 614. A unit cell is shown in more detail in FIG. 7.The dot latch 612 is a D-type flip-flop that accepts the output of thedata value 606, which is held by a D-type flip-flop 614 forming anelement of the odd dot shift register 603. The data input to theflip-flop 614 is provided from the output of a previous element in theodd dot shift register (unless the element under consideration is thefirst element in the shift register, in which case its input is theDot[x] value). Data is clocked from the output of flip-flop 614 intolatch 612 upon receipt of a negative pulse provided on LsyncL.

[0164] The output of latch 612 is provided as one of the inputs to athree-input AND gate 615. Other inputs to the AND gate 615 are the Frsignal (from the output of multiplexer 610) and a pulse profile signalPr. The firing time of a nozzle is controlled by the pulse profilesignal Pr, and can be, for example, lengthened to take into account alow voltage condition that arises due to low battery (in abattery-powered embodiment). This is to ensure that a relativelyconsistent amount of ink is efficiently ejected from each nozzle as itis fired. In the embodiment described, the profile signal Pr is the samefor each dot shift register, which provides a balance betweencomplexity, cost and performance. However, in other embodiments, the Prsignal can be applied globally (ie, is the same for all nozzles), or canbe individually tailored to each unit cell or even to each nozzle.

[0165] Once the data is loaded into the latch 612, the fire enable Frand pulse profile Pr signals are applied to the AND gate 615, combiningto the trigger the nozzle to eject a dot of ink for each latch 612 thatcontains a logic 1.

[0166] The signals for each nozzle channel are summarized in thefollowing table: Name Direction Description d Input Input dot pattern toshift register bit q Output Output dot pattern from shift register bitSrClk Input Shift register clock in - d is captured on rising edge ofthis clock LsyncL Input Fire enable - needs to be asserted for nozzle tofire Pr Input Profile - needs to be asserted for nozzle to fire

[0167] As shown in FIG. 7, the fire signals Fr are routed on a diagonal,to enable firing of one color in the current column, the next color inthe following column, and so on. This averages the current demand byspreading it over 6 columns in time-delayed fashion.

[0168] The dot latches and the latches forming the various shiftregisters are fully static in this embodiment, and are CMOS-based. Thedesign and construction of latches is well known to those skilled in theart of integrated circuit engineering and design, and so will not bedescribed in detail in this document.

[0169] The combined printhead ICs define a printhead having 13824nozzles per color. Therefore, in the case where the printhead ICs 425and 426 are equal in length, each of them includes 6912 nozzles percolor. The circuitry supporting each nozzle is the same, but the pairingof nozzles happens due to physical positioning of the MEMS nozzles; oddand even nozzles are not actually on the same horizontal line

[0170] Power and ground are provided via pads disposed along the lengthof the printhead ICs. The pads are connected to busbars 427 usingconductive adhesive, as described above.

[0171] Printhead Nozzles and Actuators

[0172] The preferred printhead nozzle arrangement, comprising a nozzleand corresponding actuator, will now be described with reference toFIGS. 46 to 55. FIG. 47 shows an array of the nozzle arrangements 801formed on a silicon substrate 8015. The nozzle arrangements areidentical, but in the preferred embodiment, different nozzlearrangements are fed with different colored inks and fixative. It willbe noted that rows of the nozzle arrangements 801 are staggered withrespect to each other, allowing closer spacing of ink dots duringprinting than would be possible with a single row of nozzles. Themultiple rows also allow for redundancy (if desired), thereby allowingfor a predetermined failure rate per nozzle.

[0173] Each nozzle arrangement 801 is the product of an integratedcircuit fabrication technique. In particular, the nozzle arrangement 801defines a micro-electromechanical system (MEMS).

[0174] For clarity and ease of description, the construction andoperation of a single nozzle arrangement 801 will be described withreference to FIGS. 46 to 54.

[0175] Each of the ink jet printhead chips 425, 426 includes a siliconwafer substrate 801. 0.35 Micron 1 P4M 12 volt CMOS microprocessingcircuitry is positioned on the silicon wafer substrate 8015.

[0176] A silicon dioxide (or alternatively glass) layer 8017 ispositioned on the wafer substrate 8015. The silicon dioxide layer 8017defines CMOS dielectric layers. CMOS top-level metal defines a pair ofaligned aluminium electrode contact layers 8030 positioned on thesilicon dioxide layer 8017. Both the silicon wafer substrate 8015 andthe silicon dioxide layer 8017 are etched to define an ink inlet channel8014 having a generally circular cross section (in plan). An aluminiumdiffusion barrier 8028 of CMOS metal 1, CMOS metal 2/3 and CMOS toplevel metal is positioned in the silicon dioxide layer 8017 about theink inlet channel 8014. The diffusion barrier 8028 serves to inhibit thediffusion of hydroxyl ions through CMOS oxide layers of the drivecircuitry layer 8017.

[0177] A passivation layer in the form of a layer of silicon nitride8031 is positioned over the aluminium contact layers 8030 and thesilicon dioxide layer 8017. Each portion of the passivation layer 8031positioned over the contact layers 8030 has an opening 8032 definedtherein to provide access to the contacts 8030.

[0178] The nozzle arrangement 801 includes a nozzle chamber 8029 definedby an annular nozzle wall 8033, which terminates in a nozzle rim 804that is circular in plan. The ink inlet channel 8014 is in fluidcommunication with the nozzle chamber 8029. At a lower end of the nozzlewall, there is disposed a moving rim 8010, that includes a moving seallip 8040. An encircling wall 8038 surrounds the movable nozzle, andincludes a stationary seal lip 8039 that, when the nozzle is at rest asshown in FIG. 46, is adjacent the moving rim 8010. A fluidic seal 8011is formed due to the surface tension of ink trapped between thestationary seal lip 8039 and the moving seal lip 8040. This preventsleakage of ink from the chamber whilst providing a low resistancecoupling between the encircling wall 8038 and the nozzle wall 8033.

[0179] As best shown in FIG. 47, a plurality of radially extendingrecesses 8035 is defined in the roof 8034 about the nozzle rim 804. Therecesses 8035 serve to contain radial ink flow as a result of inkescaping past the nozzle rim 804.

[0180] The nozzle wall 8033 forms part of a lever arrangement that ismounted to a carrier 8036 having a generally U-shaped profile with abase 8037 attached to the layer 8031 of silicon nitride.

[0181] The lever arrangement also includes a lever arm 8018 that extendsfrom the nozzle walls and incorporates a lateral stiffening beam 8022.The lever arm 8018 is attached to a pair of passive beams 806, formedfrom titanium nitride (TiN) and positioned on either side of the nozzlearrangement, as best shown in FIGS. 49 and 54. The other ends of thepassive beams 806 are attached to the carrier 8036.

[0182] The lever arm 8018 is also attached to an actuator beam 807,which is formed from TiN. It will be noted that this attachment to theactuator beam is made at a point a small but critical distance higherthan the attachments to the passive beam 806.

[0183] As best shown in FIGS. 49 and 52, the actuator beam 807 issubstantially U-shaped in plan, defining a current path between theelectrode 809 and an opposite electrode 8041. Each of the electrodes 809and 8041 are electrically connected to respective points in the contactlayer 8030 (shown in FIGS. 46 and 51). As well as being electricallycoupled via the contacts 809, the actuator beam is also mechanicallyanchored to anchor 808. The anchor 808 is configured to constrain motionof the actuator beam 807 to the left of FIGS. 46 to 48 when the nozzlearrangement is in operation.

[0184] The TiN in the actuator beam 807 is conductive, but has a highenough electrical resistance that it undergoes self-heating when acurrent is passed between the electrodes 809 and 8041. No current flowsthrough the passive beams 806, so they do not expand.

[0185] In use, the device at rest is filled with ink 8013 (FIG. 46) thatdefines a meniscus 803 under the influence of surface tension. The inkis retained in the chamber 8029 by the meniscus, and will not generallyleak out in the absence of some other physical influence.

[0186] As shown in FIG. 47, to fire ink from the nozzle, a current ispassed between the contacts 809 and 8041, passing through the actuatorbeam 807. The self-heating of the beam 807 due to its resistance causesthe beam to expand. The dimensions and design of the actuator beam 807mean that the majority of the expansion in a horizontal direction withrespect to FIGS. 46 to 48. The expansion is constrained to the left bythe anchor 808, so the end of the actuator beam 807 adjacent the leverarm 8018 is impelled to the right.

[0187] The relative horizontal inflexibility of the passive beams 806prevents them from allowing much horizontal movement with respect to thelever arm 8018. However, the relative displacement of the attachmentpoints of the passive beams and actuator beam respectively to the leverarm causes a twisting movement that causes the lever arm 8018 to movegenerally downwards. The movement is effectively a pivoting or hingingmotion. However, the absence of a true pivot point means that therotation is about a pivot region defined by bending of the passive beams806.

[0188] The downward movement (and slight rotation) of the lever arm 8018is amplified by the distance of the nozzle wall 8033 from the passivebeams 806. The downward movement of the nozzle walls and roof causes apressure increase within the chamber 8029, causing the meniscus to bulgeas shown in FIG. 47. It will be noted that the surface tension of theink means the fluid seal 8011 is stretched by this motion withoutallowing ink to leak out.

[0189] As shown in FIG. 48, at the appropriate time, the drive currentis stopped and the actuator beam 807 quickly cools and contracts. Thecontraction causes the lever arm to commence its return to the quiescentposition, which in turn causes a reduction in pressure in the chamber8029. The interplay of the momentum of the bulging ink and its inherentsurface tension, and the negative pressure caused by the upward movementof the nozzle chamber 8029 causes thinning, and ultimately snapping, ofthe bulging meniscus to define an ink drop 802 that continues upwardsuntil it contacts adjacent print media.

[0190] Immediately after the drop 802 detaches, the meniscus forms theconcave shape shown in FIG. 48. Surface tension causes the pressure inthe chamber 8029 to remain relatively low until ink has been suckedupwards through the inlet 8014, which returns the nozzle arrangement andthe ink to the quiescent situation shown in FIG. 48.

[0191] As best shown in FIG. 49, the nozzle arrangement alsoincorporates a test mechanism that can be used both post-manufacture andperiodically after the printhead is installed. The test mechanismincludes a pair of contacts 8020 that are connected to test circuitry(not shown). A bridging contact 8019 is provided on a finger 8043 thatextends from the lever arm 8018. Because the bridging contact 8019 is onthe opposite side of the passive beams 806, actuation of the nozzlecauses the priding contact to move upwardly, into contact with thecontacts 8020. Test circuitry can be used to confirm that actuationcauses this closing of the circuit formed by the contacts 8019 and 8020.If the circuit closed appropriately, it can generally be assumed thatthe nozzle is operative.

[0192] Flat Panel Display Device with Integrated Printer

[0193] A preferred embodiment of the invention is shown in FIGS. 8 to25. Referring particularly to FIGS. 8 to 15, a flat panel display unit141 includes a flat panel display 142 that is supported on a stand 143.The present invention primarily applies to flat panel displays where aviewable size of the flat panel display exceeds 40 cm measured along adiagonal of the flat panel display. The stand 143 includes a baseportion 144, which supports an arm 145 to which a housing 146 for thedisplay 142 is hingedly connected. Various control buttons 148 areprovided on the display unit 141, for controlling display functions suchas contrast, brightness, color temperature and the like.

[0194] The display unit 141 incorporates a page-width printer (describedbelow) that accepts, in the preferred embodiments shown in FIGS. 8 to32, single sheets of standard A4 or US Letter paper 149. A curved paperguide 150 causes paper exiting the printer to be directed away from thebase 144 of the display unit 141, as best shown in FIGS. 9 and 12.

[0195] The sub-components that comprise the display unit 141 are shownin exploded view in FIG. 16. A mounting plate 151 is hingedly mounted tothe arm 145 and attached to a rear cover molding 152 formed from aplastics material. The cover molding is perforated to allow convectiveair currents to cool the electronic circuitry inside the display unit141.

[0196] A metallic radio frequency interference and electromagneticinterference (RFI/EMI) shield 153 fits inside the concave side of therear cover molding 152. The shield 153 screens the various circuitryelements from external radiation, whilst reducing any radiationgenerated by the circuitry being transmitted from the display unit 141.The shield 153 takes the form of a cage with cooling holes that allowventilation of the circuitry. An additional shield 154 covers theprinthead (described below in relation to FIG. 23).

[0197] The various electronic, mechanical and electromechanicalcomponents that comprise the printer are mounted on interconnectedprinted circuit boards (PCBs) 155, as best shown in FIGS. 19 to 21. ThePCBs 155 include a printhead PCB 156, an analog converter PCB 157, abacklight inverter PCB 158, and a power supply unit (PSU) 159. The PSU159 supplies power at appropriate voltage and current to the variousother PCBs via wiring 160.

[0198] Turning to FIG. 22, the printhead PCB forms part of a printengine assembly 161. The print engine assembly 161 also includes paperfeed rollers 162, a platen 163 for supporting paper as it is fed pastthe printhead, an air pump 164 for supplying pressurized air to theprinthead, a flexible connector 147 for supplying data from the printengine chips on the print engine PCB to the printhead, an ink deliverybus 165, and a print engine controller (SoPEC) chip 166. The feedrollers 162 are driven by a paper drive motor 197 and drive assembly198.

[0199] As shown in FIG. 23 (in which the platen and feed rollers areremoved for clarity), the print engine assembly 161 also includessupport metalwork 167 for mounting the various components, copperbusbars 168 for supplying power from the power leads 169 to theprintheads, and flexible paper guide fingers 170. Ink channel moldings171 route ink from the ink delivery bus 165, which also includeselectrical contacts 173 that enable communication between an inkcartridge (described below) and the print engine assembly. It will benoted that the present embodiment includes two printhead segments 174and 175 of equal length that together form a pagewidth printhead. Asdescribed earlier in this document,

[0200] Referring back to FIG. 16, a metal paper chute 176 is provided toguide paper behind the display and down to the printhead. A metalchassis 177 is provided to support the display 142, which is surroundedand protected by a plastic front bezel molding 178. A menu PCB 179 holdsthe menu buttons 148 and associated status LEDs.

[0201] As best shown in FIG. 10, the display unit 141 is provided withpower via a mains cord 180 and associated mains plug 181. The mains plug181 is inserted into mains socket 182, which is shown in FIG. 17 withthe mains plug 181 removed. The mains socket 182 is hard-wired into thePSU 159.

[0202] A video input cable 183 and associated video plug 184 supplyvideo data from a computer. The video plug 184 is inserted into a videosocket 185, which is shown in FIG. 17 with the video plug 184 removedfor clarity.

[0203] A data connection in the form of a USB 2 link is provided by wayof a data cable 186 and associated data plug 187. The plug 187 isinserted into a USB 2 compliant data socket 188, which is shown in FIG.17 with the data plug 187 removed for clarity.

[0204] As shown in FIG. 21 an ink cartridge 189 containing the variousinks required for operation of the printer releasably engages the inkdelivery bus 165 via an aperture 190 (FIG. 16) formed in the rearmolding 152. The cartridge is preferably held in position by aninterference fit, although a positive retaining mechanism such as a clipcan be supplied in alternative embodiments. As best shown in FIG. 21,the ink delivery bus 165 includes a plurality of fluid ports 191 thatengage with corresponding fluid outputs (not shown) formed in thecartridge. In the embodiment shown, each fluid port 191 includes ahollow needle 192 that penetrates a seal (not shown) in thecorresponding fluid output. The seal can be an annular resilient sealwith a frangible membrane, or simply a frangible membrane thatself-seals around the needle 192 as the cartridge 189 is inserted intoan operative position.

[0205] The cartridge 189 contains the inks necessary for its use withthe printer. The various possible combinations of colored inks (such asCMY), black ink, infrared ink and a fixative are described elsewhere inthis document. The cartridge 189 also includes a QA (“Question-Answer”)chip that is configured to store information accessible by the SoPECchip 166, such as ink levels remaining (preferably on a per-ink basis),types of ink contained in the cartridge, security data for ensuring thecartridge is compliant with the printer's needs and any other data thatmight be useful for the operation of the printer based on the particularcartridge inserted. The QA chip is electrically connected to a set ofcontacts (not shown) that operatively engage the electrical contacts 173on an edge of the ink delivery bus 165. The electrical contacts allowinformation to be read from the QA chip in the cartridge 189 asrequired. This can be when the cartridge is first inserted, and possiblyperiodically thereafter. In the preferred embodiment, the SoPEC chip 166can also write back to the cartridge. Typically, this will involvedetermining the amount of ink used and then updating the QA chip in thecartridge.

[0206] A number of other elements of the display unit 141 not shown inother Figures are shown in FIG. 44. It will be noted that the flat paneldisplay 142 is preferably a Thin Film Transistor (TFT) Liquid CrystalDisplay (LCD). However, it will be understood that the particulartechnology employed in the flat panel display 142 is not critical to theinvention. The flat panel display 142 can therefore be of any othertype, including those using Organic Light Emitting Diode (OLED), FieldEmission Display (FED) and Plasma Display Panel (PDP) technologies.

[0207] As shown in FIG. 44 the display unit includes row drivers 193 andcolumn drivers 194 that are provided with input signals by an imageprocessor 195 located on the analog converter PCB 157. The imageprocessor receives display data from a personal computer (not shown) viathe video socket 185. The fluorescent backlight inverter PCB 158 drivesa fluorescent backlight 196.

[0208] The USB input 188 (FIG. 17) provides data in accordance with theUSB 2 protocol to the SoPEC chip 166. The image processor 195 can alsoprovide data to the SoPEC chip 166, as described in detail below.

[0209] Operation of the display unit will now be described withreference to FIG. 44. Display data is received from a personal computer,or other suitable video data source, via the video input socket 185. Thedisplay data is provided to the image processor 195, which processes andconverts it into a format suitable for supply to the row drivers 193 andcolumn drivers 194. These drive the various TFTs required to display theimage on the flat panel display 142. The fluorescent backlight 196provides illumination from behind the TFTs, thereby enhancing visibilityof images displayed. Various display settings, such as contrast,brightness and resolution, can be altered by a user via the controls148.

[0210] The USB input socket 188 accepts USB formatted data from aconnected personal computer, such as personal computer 102 in FIG. 1. Itwill be appreciated that this data can come from any other suitablesource, such as a network connection or any other data communicationlink.

[0211] Upon receipt, the data is forwarded via an internal USB link tothe printhead PCB 156 and the SoPEC chip 166. The data is decompressedand formatted in accordance with the steps shown in FIG. 1, using thehardware 232 described in relation to FIG. 2. The formatted data isforwarded from the SoPEC chip 166 to the Memjet printheads 174 and 175.The data is then printed onto the paper 149 as it is driven past theprintheads.

[0212] In the preferred embodiment, the print button 200 (FIGS. 8 and 9)can be used to generate a printout of the presently displayed image.This enables a printout of the screen to be taken without the need touse a mouse, keyboard or other control device associated with thepersonal computer 102.

[0213] The invention has a number of advantages over the prior art. Thecombination of a printer and flat panel display saves a considerableamount of room compared to a separate display and printer combination.The printed matter, in the preferred embodiment, is ejected right infront of the user, unlike the case with prior art printers which are,for the most part, too bulky to be placed directly in front of the user.

[0214] In the particularly preferred embodiment described, the pagewidthnature of the printer and its relatively compact dimensions comparedwith inkjet and laser printers respectively mean that high qualityprinting can be provided without substantially increasing the size ofthe flat panel display casing. Given that a major advantage of flatpanel displays is their compactness, this can be considered a majorfeature of the preferred embodiment. With the use of a pagewidthprinthead, there is less vibration than with a reciprocating inkjetprinthead, resulting in a more stable image for a user viewing thedisplay whilst printing.

[0215] An alternative embodiment of the invention is shown in FIG. 26,in which like numerals indicate features corresponding to thosedescribed in relation to the embodiment of FIGS. 8 to 25. The embodimentof FIG. 26 is a duplex printer, which includes a pair printheads 304 and305. The printheads are preferably of the same construction as thesingle printhead, each comprising two printhead segments. In thepreferred embodiment, each of the printheads 304 and 305 has its ownassociated SoPEC device.

[0216] In operation, the embodiment of FIG. 26 prints onto both sides ofthe paper 149 as it is fed between the printheads 304 and 305.

[0217] A further embodiment is shown in FIGS. 27 and 28, in which likenumerals indicate features corresponding to those described in relationto the embodiment of FIGS. 8 to 25. The embodiment includes amulti-sheet feeder 312 that enables a single sheet at a time to be takenfrom a stack of paper and fed past the printhead. The feeder 312 is bestshown in FIG. 28, and includes a paper stop 205 that holds a stack ofpaper 203 in position. The preferred capacity of the stack 203 is about50 sheets, although other capacities can be used. A flexible shim 206extends across the top of the paper stop 205, terminating in an edgeadjacent and below a pickup roller 204. The pickup roller 204 isgenerally circular in cross-section, but incorporates a flat portion313.

[0218] In use, the paper stack 203 is loaded such that it rest on theflexible shim 206, which is in turn supported by the paper stop 205. Thepickup roller 204 is positioned rotationally such that the flat portion313 (FIG. 28) is aligned with the nearest piece of paper in the stack.The pickup roller 204 is then rotated clockwise (relative to FIG. 28),until the rounded portion engages the piece of paper. As this happens,friction between the paper and the roller increases, causing a downwardforce on the paper. The flexible shim 206 causes the sheet of paper tobe separated from the stack 203 and driven downwards towards the feedrollers 162. As the paper engages the feed rollers, the flat spotrotates back into the position shown in FIG. 28, which reduces thefriction between the pickup roller and the paper, thereby enabling thefeed rollers to push the paper past the printhead.

[0219] It will be appreciated that any other known paper feedingmechanisms can be employed for taking a single sheet from a stack andfeeding it for printing. It will also be appreciated that a duplexprinthead arrangement such as that shown in FIG. 26 can also be employedwith a multi-sheet feed mechanism.

[0220] Another embodiment is shown in FIG. 29, in which the sockets 182,185 and 188 are positioned in the base portion 144 of the display unit.This enables a neater arrangement of cables, since there is no need toroute them all the way up to the rear molding 152. Rather, internalwiring takes the power and data from the sockets to the relevantcomponents via the interior of the arms 145.

[0221]FIG. 30 shows another embodiment, in which the base portion 144acts as a data hub. Circuitry (not shown) in the base portion 144 allowsthe USB connection enabled by socket 188 to send and receive data to andfrom other devices via data hub connectors 207. This enables anythingfrom network to peripheral devices to be connected via the base portion144, rather than needing to access ports or sockets on the personalcomputer to which the display unit is connected. This can beadvantageous given that ports and sockets on personal computers areoften positioned in relatively difficult to access places. Often, thecomputer device itself is positioned out of the way, such as underneatha desk, which can contribute to this inconvenience of making dataconnections in the prior art.

[0222] Yet another embodiment, shown in FIG. 31, the ink bus 165 ispositioned such that the ink cartridge 189 is positioned on the mountingplate 151.

[0223]FIG. 32 shows another embodiment of the invention, in which theink cartridge 189 is positioned in the base portion 144 of the displayunit. In this case, the arms 145 also include ink conduits for supplyingink from the cartridge 189 to the printer. In some cases, it may benecessary to provide some form of pump or other pressurizationarrangement to push the ink upwards through the conduits in the arms145.

[0224] One Touch Print Button

[0225] A desktop printer attached to a personal computer (PC) mayusefully incorporate an “Print” button which when pressed causes theactive Windows application on the PC to print its entire active documentto the printer, without an intervening print dialog.

[0226] As a variation on this theme, when the printer is embedded in aflat-panel display (FPD), then the Print button may be incorporated inthe display.

[0227] By active application we mean the application whose window istop-most, and with which the user it typically currently interacting. Byactive document we mean the document displayed in the activeapplication's top-most window.

[0228] When the Print button is incorporated in a printer, it isimportant that the button initiates printing to that printer. When thePrint button is incorporated in a display, it is reasonable for it toinitiate printing to the default printer, which may or may not beconfigured to be the in-panel printer.

[0229] Windows Printing Background

[0230] There is no single standard way under Microsoft Windows toprogrammatically instruct the active application to print its activedocument to the default or to a designated printer. However, there areseveral mechanisms which may be exploited, covering most applicationtypes.

[0231] Although not explored here, comparable mechanisms exists underother operating systems and windowing systems, including Apple MacOS,Unix, X Windows, Linux etc. It should be appreciated by those skilled inthe art that the invention is not limited to use with any particularhardware, operating system or software combination.

[0232] Printing User Interface

[0233] Most Microsoft Windows applications, as a matter of convention,provide a fairly standard printing user interface. This consists of: (a)a Print option on the File menu, usually accessible via the two keyboardsequences ALT,F,P and CTRL+P, which displays a print dialog to print thecurrent document; and (b) a Print tool on the toolbar (shown as aprinter icon) which prints the current document to the default printerwithout displaying the print dialog. Dialog-less direct printing has nostandard keyboard shortcut.

[0234] If the active application is receptive to a keyboard sequence inthis way, then a client application can instruct it to print by queuingthe appropriate keyboard events (using the keybd_event or SendInput SDKfunctions) or by queuing the appropriate keyboard messages (using theAttachThreadInput, GetFocus, and PostMessage SDK functions).

[0235] Direct printing can be simulated by appending a carriage-returnto the keyboard sequence, causing the print dialog to be completedwithout further user input.

[0236] Automation

[0237] Some Windows applications, including Microsoft Officeapplications such as Word and Excel, expose an Automation interface(formerly known as OLE Automation), which allows them to be controlledby a separate application. For example, Word (like many other Microsoftapplications) exposes a PrintOut method which can be invoked on theactive document to print the document directly. A client application candiscover an open Word document and print it in this way. The applicationcan designate a particular printer by assigning the name of the printerto Word's ActivePrinter property prior to invoking the PrintOut method.Automation servers such as Office applications register runninginstances of themselves in the Running Object Table (ROT).Multi-instance applications (such as Excel and some versions of Word)are only able to create a single application entry in the ROT. However,multi-instance applications typically also register each of their opendocuments separately in the ROT, allowing the client application to findthe application instance corresponding to a particular document via thedocument's entry in the ROT.

[0238] The client application can iterate through the ROT, attach toeach server application of interest in turn, and identify whether theapplication is associated with the foreground window. If the serverapplication is associated with the foreground window (as identified bythe GetForegroundWindow SDK function), then the client application caninvoke the application's PrintOut method (or equivalent) to print theactive document. In the case of a single-instance application (such asPowerPoint), the client application attaches to the server applicationdirectly via the ROT entry. In the case of a multi-instance application(such as Excel), the client application attaches to the serverapplication via a document entry in the ROT.

[0239] The Windows SDK provides standard functions for obtaining apointer to the ROT and iterating through it. Application and documententries in the ROT are easily recognised since each entry is associatedwith a class-specific programmatic identifier. For example, a Wordapplication has the programmatic identifier “Word.Application.x” (wherex indicates the application version), and a Word document has theidentifier “Word.Document.y” (where y indicates the document version).An application entry in the ROT conventionally includes theapplication's class identifier in its name, from which the correspondingprogrammatic identifier can be obtained via the Windows registry. Adocument entry in the ROT allows its programmatic identifier to bediscovered via the class identifier associated with the document'spersistence interface.

[0240] Because there are several ways to programmatically instruct thecurrent application to print its active document to the default or to adesignated printer, and because no single way is optimal for allapplications, support for a “Print” button is best provided (in thisembodiment) by invoking the mechanism most appropriate to the currentapplication according to the current application's type.

[0241] In its simplest form, this consists of first trying to find theactive application in the ROT, specifying the target printer by settingthe active application's ActivePrinter property, and invoking the activeapplication's PrintOut method. If the active application is not found inthe ROT, then the fallback consists of queuing the standardprint-invocation keyboard sequence (i.e. Control key down, P key down, Pkey up, Control key up, CR key down, CR key up).

[0242] In a more sophisticated implementation, a table of applicationsis created which lists the mechanism most appropriate to eachapplication type, i.e. Automation versus keyboard sequence, and exactapplication properties and methods to use, or exact keyboard sequence tosend. Automation server applications are identified by theirprogrammatic identifiers, while conventional applications are identifiedby their names. For example, Word is identified by its programmaticidentifier “Word.Application.x”, while Notepad is identified by its name“Notepad”. It is straightforward to identify the foreground window (viathe GetForegroundWindow SDK function) and extract the name of thecorresponding active application from the window's title (via theGetWindowText SDK function).

[0243] The “Print” button can be a physical momentary switch or it canbe simulated via another interface on the printer (or FPD) such as atouch-sensitive display. In any case, when the user presses the printbutton, an event is relayed to a background application on the PC whichinvokes the corresponding printing function as described above. Thebackground application may already be executing, i.e. awaiting events,or it may be activated by the user's act of pressing the “Print” button.The button event can be relayed by the control software in the printer,via the printer's communications interface and its printer driver, andthence to the background application. Alternatively cacan be relayed viaits own communications interface and driver, in which case the driverand the background application may be one and the same. For example, theprint button can be provided in the form of a separate Universal SerialBus (USB) device on the USB bus, but may share the physical USBconnection between the printer (or FPD) and the PC.

[0244] In the preferred embodiment, the background application iscapable of handling the “Print” buttons of multiple devices. To allow itto distinguish multiple buttons, each button event in this embodimentuniquely identifies its originating button. An event may include aunique identifier associated with the printer in which the button isembedded, or a unique identifier associated with the button itself,retrieved from non-volatile storage attached to the button.

[0245] In cases where the target printer can be selected by setting theactive server application's ActivePrinter property, the backgroundapplication must know which printer name to specify. Since it may bedifficult for the background application to know the name of the printerassociated with a particular “Print” button it is servicing, it isuseful to allow the user to associate a printer with each button,indexed by the button's unique identifier. If a button is pressed whichhas no associated printer, then the background application can determinehow many printers are configured on the PC. If there is only oneprinter, then the application has no need to specify a printer since theone printer must be the default printer. If there are several printers,then the application can prompt the user to select one, and can thenrecord the association between the selected printer and the button. Itis straightforward for the background application to enumerate theavailable printers using the EnumPrinters SDK function.

[0246] Various exemplary, non-limiting aspects of the invention areforeshadowed in the following numbered paragraphs:

1. A printing and display device comprising: a flat panel display fordisplaying images from a computer; and a printer, the printer includinga printhead for printing onto the paper.
 2. A printing and displaydevice as claimed in claim 1 wherein a viewable size of the printing anddisplay device exceeds 40 cm measured along a diagonal of the printingand display device.
 3. A printing and display device as claimed in claim1, wherein the printer includes at least two the printheads, theprintheads being disposed on either side of a path through which printmedia is fed for printing, thereby enabling substantially simultaneousprinting of both sides of the print media.
 4. A printing and displaydevice as claimed in claim 1, configured to receive print data to beprinted, and display data to be displayed, from a computer system.
 5. Aprinting and display device as claimed in claim 3, wherein the printingand display device includes a connection configured to allow releasableoperative connection of the computer system to the printing and displaydevice, for receiving the print data and the display data from thecomputer system.
 6. A printing a display device as claimed in claim 4,wherein the connection includes at least one socket for accepting atleast one corresponding data cable.
 7. A printing and display device asclaimed in claim 4, wherein the connection includes a wireless receiverfor receiving the print data and/or the display data.
 8. A printing anddisplay device as claimed in claim 4, wherein the connection is aUniversal Synchronous Bus (USB) connection.
 9. A printing and displaydevice as claimed in claim 1, further including a paper feed mechanismfor feeding paper to the printhead for printing, the printhead beingarranged to print onto the paper.
 10. A printing and display device asclaimed in claim 8, wherein the paper feed mechanism is configured toposition the paper substantially parallel in at least one direction withrespect to a plane defined by the flat panel display.
 11. A printing anddisplay device as claimed in claim 8 or 9, wherein the paper feedmechanism is configured to accept a single sheet of paper at a time forprinting.
 12. A printing and display device as claimed in claim 8 or 9,wherein the paper feed mechanism includes a paper separator for feedinga single sheet of paper to the printhead from a stack of sheets ofpaper.
 13. A printing and display device as claimed in claim 1, whereinthe printer is a process color printer.
 14. A printing and displaydevice as claimed in claim 1, wherein the printer is an inkjet printer.15. A printing and display device as claimed in claim 13, wherein theprinter has more than 5,000 inkjet nozzles.
 16. A printing and displaydevice as claimed in claim 1 or 14, wherein the printer is a page-widthprinter.
 17. A printing and display device as claimed in claim 1,including at least two of the printheads, the printheads being disposedon either side of a path through which the paper is fed for printing,thereby enabling substantially simultaneous printing of both sides of asheet of paper.
 18. A printing and display device as claimed in claim 1,configured to enable printing of standard A4 or Letter sized sheets ofpaper.
 19. A printing and display device as claimed in claim 1,configured such that paper to be printed is fed manually into a paperpath that directs the paper from a region adjacent the upper edge of theflat panel display, past the printhead for printing, then out of thedevice adjacent a lower edge of the flat panel display.
 20. A printingand display device as claimed in claim 1, further including a curvedpaper guide disposed, when the device is in use, beneath the flat paneldisplay, such that the paper that has been printed is urged horizontallyas it exits the device.
 21. A printing and display device as claimed inclaim 1, wherein the flat panel display is of one of the followingtypes: a. Liquid Crystal Display (LCD); b. Organic Light Emitting Diode(OLED) c. Field Emission Display (FED) d. Plasma Display Panel (PDP) 22.A printing and display device as claimed in claim 1, wherein theprinthead is configured to receive halftoned print data to be printedonto the print media.
 23. A printing and display device as claimed inclaim 1, further including a halftoning unit for generating halftonedimage data and supplying it to the printhead for printing.
 24. Aprinting and display device as claimed in claim 1, wherein the printheadis configured to print photographic images.
 25. A printing and displaydevice as claimed in claim 1, wherein the printhead is configured toprint image and text data.
 26. A printing and display device as claimedin claim 3, wherein the computer system is a personal computer.
 27. Aprinting and display device as claimed in claim 1 further comprising: aflat panel display for displaying images from a computer; a stand forholding the flat panel display in an operative position; and a printer,the printer including a printhead for printing onto paper; wherein thestand includes at least one receptacle configured to accept at least onereplaceable ink cartridge for supplying ink to the printer.
 28. Aprinting and display device as claimed in claim 1 further comprising: adata connection for receiving print data from a computer; a flat paneldisplay for displaying images received from a computer; a printer, theprinter including a printhead for printing onto paper on the basis ofthe print data; and a data connection hub configured to allow connectionof at least one data-receiving device to the printing and displaydevice, enabling the data-receiving device to receive data from thecomputer.
 29. A printing and display device as claimed in claim 1further comprising: a flat panel display; and a printer, including aprinthead for printing onto paper; the device being configured suchthat, during printing, the paper being printed passes between the flatpanel display and the printhead, or passes behind the flat panel displayand the printhead relative to a viewing position of the flat paneldisplay.
 30. A printing and display device as claimed in claim 1 furthercomprising: a flat panel display; a printer, including a printhead forprinting onto paper; a multi-sheet paper holder; a paper sheet separatorconfigured to separate a single paper sheet from the paper in the paperholder for supply to the printhead.
 31. A printing and display device asclaimed in claim 1 further comprising: a flat panel display fordisplaying images from a computer; and a printer, the printer includingat least two the printheads, the printheads being disposed on eitherside of a path through which print media is fed for printing, therebyenabling substantially simultaneous printing of both sides of the printmedia.
 32. A printing and display device as claimed in claim 1 beingconfigured to receive documents to be printed from a computer system,the printing and display device including an interface, and beingconfigured to: receive, via the interface, input from a user indicativeof a print command; send, from the printing and display device to thecomputer system, a print request; receive, from the computer system andin response to the print request, a document to be printed; and printthe document.